Strain relief

ABSTRACT

The invention is directed to an improved unitary, integral, detachable strain relief. At least one generally arcuate clamping arm is resiliently coupled to a generally tubular body member adapted to be detachably secured about the outer surface of a conector or similar article. Strap receiving means project outwardly from its associated clamping arm to at least partially retain therein a strap or band disposed thereabout to secure the clamping arm to a cable or a plurality of insulated electrical wires positioned immediately adjacent thereto and extending outwardly from the connector.

United States Patent [72] lnventor Edward F. Rynk Linden, NJ. 21 1 Appl.No. 32,162 {22] Filed Apr. 27, 1970 [45] Patented Nov. 23. 1971 [73]Assignee Thomas & Betts Corporation Elizabeth, NJ.

[54] STRAIN RELIEF 6 Claims, 11 Drawing Figs.

[52] US. Cl 339/107 [51] Int. Cl 1101! 13/58 [50] Field ofSearch339/103, 104, 107, 62, 206, 116, 208, 101

[56] References Cited UNITED STATES PATENTS 1.292.911 1/1919 Stacey339/103 C 2,830,282 4/1958 Swanetal 3,422,392 1/1969 Woods PrimaryExaminerRichard E. Moore A!!0rneyDavid Teschner PATENTEDunv 2 3 an SHEET1 OF 2 INVIfN'IUR EDWARD F RYNK ATTORNEY PATENTEDunv 2 3 1911 SHEET 2 OF2 ATTORNEY STRAIN RELIEF BACKGROUND OF THE INVENTION 1. Field of theInvention The invention is directed to the field of strain reliefdevices, and principally to unitary, integral strain relief devicesdetachably connectable to an electrical connector or similar article.

2. Description of the Prior Art Strain relief devices according to theprior art generally comprised a plurality of discrete componentsrequiring separate-means for coupling the components one to another andto the cable or similar item and connector about which said strainrelief is to be secured. In practice, the individual componentscomprising such device were required to be positioned and maintained inproper relation relative to the article about which the device was to besecured, prior to the disposition and tightening thereabout of a strapor other similar securing means. Such operation was generally awkward,timeconsuming and uneconomical. Additionally, the separate componentswere subject to loss or misplacement, prior to assembly, furtherincreasing the cost thereof. Commonly employed strain reliefs accordingto the prior art were also formed of generally rigid metallic materialwherein filler means such as tape or other similar wrapping material wasrequired to be wrapped around that portion of the insulated electricalconductors or electrical cable immediately adjacent the cable clampingportion of the strain relief in an attempt to compensate for varyingdiameter wire bundles about which the strain relief was to be secured,and to protect the relatively vulnerable electrical insulating materialcovering said conductors from the generally sharp edges of the clampingportion of the strain relief. I

SUMMARY OF THE INVENTION:

The invention is directed to an improved strain relief device whichovercomes the problems noted above with respect to prior art devices byproviding a unitary, integral, detachable strain relief device which issimpler, less expensive, safer, and more efficient than such devices.Resiliently coupled to a generally tubular body member and integraltherewith, is preferably a pair of generally arcuate clamping arms, theinner generally concave surfaces of which define a substantiallyannular, variable cable receiving cavity. The inner surface of the bodymember may be threaded or have disposed thereon other similar projectingportions to permit said member to be detachably secured and tightenedabout the externally threaded portion of an electrical connector or thelike. The body member may be comprised of a pair of generally arcuatemembers hingedly coupled together by an integral web portiontherebetween. A raised portion projecting outwardly from the clampingarm of the strain relief device provides strap receiving means and maybe either apertured or formed into a hook like member to receive and atleast partially restrain therein a strap or similar item disposedthereabout for securing the clamping arms about an electrical cable orplurality of insulated electrical conductors extending outwardly fromthe connector. A longitudinally aligned recess may be provided in theouter surface of the body member wherein the body member may beconveniently parted along the recess permitting the device to bereadily-disposed about a preexisting connected cable or conductorbundle. It is therefore an object of this invention to provide animproved strain relief device.

It is another object of this invention to provide an improved unitary,integral strain relief device for insulated electrical conductors or thelike.

It is a further object of this invention to provide an improved strainrelief device detachably connectable to the outer surface of a connectoror similar item.

It is still another object of this invention to provide an improvedstrain relief device detachably securable about a connector or similaritem and a plurality of electrical conductors or the like extendingtherefrom.

It is still a further object of this invention to provide an improvedunitary, integral strain relief device having a conveniently separablebody portion for positioning said device about a cable or plurality ofelectrical conductors previously terminated to a connector or the like.

Other objects and features of the invention will be pointed out in thefollowing description and claims and illustrated in the accompanyingdrawings, which disclose, by way of example, the principle of theinvention and the best mode which has been contemplated for carrying itout.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawings FIG. 1 is a side viewof a strain relief device constructed in accordance with the concepts ofthe invention.

FIG. 2 is a side view of the device of FIG. 1 assembled about aplurality of electrical conductors.

FIG. 3 is a side view of another embodiment of a strain relief deviceconstructed in accordance with the concepts of the invention.

FIG. 4 is a side elevation view of another embodiment of a strain reliefdevice constructed in accordance with the concepts of the invention.

FIG. 5 is a side elevation view of the device of FIG. 4 assembled abouta plurality of electrical conductors.

FIG. 6 is a side elevation view of still another embodiment of a strainrelief device constructed in accordance with the concepts of theinvention.

FIG. 7 is a front elevation view of still a further embodiment of astrain relief device constructed in accordance with the concepts of theinvention.

FIG. 8 is a side elevation view of still another embodiment of a strainrelief device constructed in accordance with the concepts of theinvention.

FIG. 9 is a perspective view of the strain relief device of FIG. 8.

FIG. 10 is a rear elevation view of still another embodiment of astrain'relief device constructed in accordance with the concepts of theinvention.

FIG. 11 is a side elevation view of the strain relief device of FIG. 10.

Similar elements are given similar reference characters in each of therespective drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS. 1 and 2,there is shown an improved strain relief device 20 constructed inaccordance with the concepts of the invention. Strain relief device 20comprises a generally, tubular body member 22 having disposed about theouter surface thereof a plurality of generally equally spaced generallyelongated protrusions 28 in longitudinal axial alignment with thelongitudinal axis of body member 22. The inner surface of body member 22is threaded as at 26 for threaded engagement with a threaded connectorsuch as 38. Protrusions 28 provide convenient gripping means whereinbody member 22 may be securely tightened about connector 38, therebyrigidly coupling strain relief device 20 to the connector 38. Althoughthe inner surface of body member 22 of strain relief 20 is illustratedas threaded, other forms of regular or irregular circumferentiallydisposed protruding configurations may be provided for permitting bodymember 22 to interferingly engage appropriately matched configurationson the outer surface of a connector such as 38 wherein body member 22may be rigidly secured thereto without departing from the spirit of theinvention. Further, it should be understood that a series of flattedsurfaces may be substituted for protrusions 28 of body member 22 tocooperatingly accept the jaws of a wrench or similar tool for securelytightening body member 22 about a connector such as 38, without againdeparting from the spirit of the invention. Integral with body member 22and extending generally longitudinally from the second end 24 thereofare a pair of resilient coupling means such as generally elongatedweblike members 30 terminating in a pair of generally arcuate clampingarms 32 each of which is integrally coupled to its associated resilientcoupling means 30. The opposing generally concave inner surfaces ofclamping arms 32 at least partially define a generally annular cablereceiving orifice securable about the outer surface of an insulatedelectrical conductor or the like. Projecting outwardly from the outersurface of each clamping arm 32 is a raised portion 34 having agenerally elongated transverse slot 36 therethrough, the raised portion34 together with slot 36 thereby comprising a strap receiving meansadapted to receive therein a strap such as 40 or similar tie fortightening clamping arms 32 about an insulated electrical conductor or aplurality of insulated electrical conductors such as 42, in a mannermore clearly shown in FIG. 2.

Turning now to FIG. 3, there is shown a modification of a strain reliefdevice 44 constructed in accordance with a further embodiment of theinvention. A raised portion 48 projects outwardly from the outer surfaceof its associated clamping arm 46 defining a generally hooklikeprotrusion, the open end of which is directed to the left of FIG. 3,towards body member 52, providing a modified form of strap receivingmeans. A strap such as 40, as illustrated in FIG. 2, may be readilydisposed about clamping arms 46 and at least partially tightened andpositioned under the hooklike projections 48 and further tightened torigidly secure clamping arms 46 about a plurality of conductors such as42 of FIG. 2 in a manner as previously described with respect thereto.Body member 52 and resilient coupling means 53 duplicate essentiallysimilar elements 22 and 30 of FIGS. 1 and 2.

Referring now to FIGS. 4 and 5, there is shown a further embodiment of astrain relief device 54 constructed in accordance with the concepts ofthe invention. Extending between the first end 48 and the second end 60of body member 56 in aligned longitudinal axial relation thereto is arecess 62, providing a reduced cross-sectional area in the vicinitythereof to permit body member 56 to be readily parted along recess 62for convenient disposition about the outer surface of a connector suchas 76. A plurality of generally uniformly spaced apart discreteprojections such as 64 are circumferentially disposed in twosubstantially parallel rows about the outer surface of body member 56forming therebetween a guide which may be utilized to at least partiallyrestrain therein a strap such as 74 disposed circumjacent body member 56to rigidly secure the previously parted body member 56 about the outersurface of a connector such as 76. A pair of generally arcuate clampingarms 68 are integrally coupled to body member 56 by resilient couplingmeans 66 in a manner similar to that heretofore described with respectto FIGS. 1 and 2. Strap receiving means 72 and raised portions 70 shownin FIG. 4 duplicate substantially similar portions described above withreference to strain relief device 20 of FIGS. 1 and 2. A typical exampleof the manner in which a strain relief device such as 54 may be employedis shown in FIG. 5. Strap 74 is disposed about body member 56 and drawnup tightly to secure body member 56 to the outer surface of a connectorsuch as 76. Projecting portions 64 circumferentially disposed about theouter surface of body member 56 provide guide means for strap 76, toinsure the selective positioning and restraining thereof within thedesired portion of body member 56. Strap 78 serves to maintain clampingarms 68 in tight intimate engagement with conductors 80 thereby insuringa minimum of relative movement therebetween.

Turning now to FIG. 6, there is shown a further embodiment of a strainrelief device 82 constructed in accordance with the concepts of theinvention. Strain relief device 82 is substantially similar to device 54of FIGS. 4 and 5, differing, however, in the structural contour definingthe pair of strap receiving means 86 projecting outwardly from anassociated pair of clamping arms 84. As shown, each strap receivingmeans 86 comprises a hooklike projection, the open end 88 of which isdirected towards the body member 90, similar to por tion 48 of FIG. 3,to at least partially engage and restrain a strap or similar iteminterposed therein.

Referring now to FIG. 7, there is shown a further embodiment of a bodymember 94 of a strain relief device 92 constructed in accordance withthe concepts of the invention. A recess 96 is longitudinally disposedwithin the outer surface of body member 94 permitting body member 94 tobe readily parted thereat. A plurality of inwardly directed generallyarcuate portions such as 98, integral with the inner surface 102 of bodymember 94, are adapted to deformably engage matingly cooperablecomplementary portions of a connector or similar device about whichstrain relief device 92 is to be secured.

Turning now to FIGS. 8 and 9, there is shown a further embodiment of aunitary, integral strain relief device 104 constructed in accordancewith the concepts of the invention. A pair of generally arcuate portions112 define a body member 106 adapted to be detachably secured about theouter surface of a connector or similar item. An elongated web portion110 extends between a pair of resilient coupling means 108 integrallyjoining said means, each of which is integrally coupled to and dependsfrom its associated generally arcuate member 112. The arcuate bodymember portions 112 are thus radially deformable and the inner surfacesthereof define a variable connector receiving orifice wherein said bodymember 106 may be disposed circumjacent a connector such as 76 of FIG. 5and secured thereabout about by strap means such as 74 of FIG. 5tightened about the outer surface of body member 106 in a manner similarto that shown therein. The inner surface of each of the generallyarcuate portions 112 of body member 106 may be threaded as at 114 formating engagement with a complementarily contoured outer surface of aconnector or similar article. It should be understood that although onlytwo such portions 112 are shown, a plurality of generally arcuate bodymember segments may be provided, adjacently coupled one to another ingenerally annular fashion without departing from the spirit of theinvention.

Turning now to FIGS. 10 and 11, there is shown a strain relief device116 constructed in accordance with still another embodiment of theinvention. The generally tubular body member 118 of strain relief device116 is slit longitudinally of the axis thereof, as at 121. A web portion122, in opposing diametrical relation to slit 121, and substantiallynarrower than the width of body member 118 serves as a convenient hingemeans coupling together the separable, generally arcuate portions 120 ofbody member 118, whereby arcuate portions 120 may be readily deformedradially outwardly for convenient disposition about a range of selectiveconnectors. The remaining structure of strain relief device 116,comprising a pair of clamping arms 124 integrally coupled to body member118 by a pair of associated resilient coupling means 126 duplicatesimilar elements 68 and 66 of FIGS. 4 and 5.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

Iclaim:

1. A strain relief device comprising: a generally tubular body memberhaving a first end and a second end; at least one generally arcuateclamping arm; and resilient coupling means extending outwardly from saidsecond end of said body member generally longitudinally of the axisthereof, coupling said clamping arm to said body member; said clampingarm and said resilient coupling means, together with said body member,being formed of a unitary integral structure; said clamping arm havingstrap receiving means having an aperture therethrough disposed generallynormal to the plane thereof and projecting generally outwardlytherefrom, adapted to selectively engage and at least partiallydetachably confine therein a strap or similar item disposed about saidclamping arm to detachably secure said arm to a cable or similar itemadjacent thereto; the inner surface of said body member having a seriesof interruptions thereon for intimately engaging the outer surface of aconnector or similar item.

2. A strain relief device comprising: a generally tubular body memberhaving a first end and a second end; at least one generally arcuateclamping arm; and resilient coupling means extending outwardly from saidsecond end of said body member generally longitudinally of the axisthereof, coupling said clamping arm to said body member; said clampingarm and said resilient coupling means, together with said body member,being formed of a unitary integral structure; said clamping arm havingstrap receiving means comprising a hooklike projection in generallyaligned axial relation with the longitudinal axis of said body member,the open end of said hooklike projection being directed generallytowards said body member and adapted to selectively engage and at leastpartially detachably confine therein a strap or similar item disposedabout said clamping arm to detachably secure said arm to a cable orsimilar item adjacent thereto; the inner surface of said body memberhaving a series of interruptions thereon for intimately engaging theouter surface of a connector or similar item.

3. A strain relief device comprising a generally tubular body memberhaving a first end and second end; at least one generally arcuateclamping arm; and resilient coupling means extending outwardly from saidsecond end of said body member generally longitudinally of the axisthereof, coupling said clamping arm to said body member; said clampingarm and said resilient coupling means, together with said body member,being formed of a unitary integral structure; said clamping arm havingstrap receiving means projecting generally outwardly therefrom, adaptedto selectively engage and at least partially detachably confine thereina strap or similar item disposed about said clamping arm to detachablysecure said arm to a cable or similar item adjacent thereto; the innersurface of said body member having a series of interruptions thereon forintimately engaging the outer surface of a connector or similar item;said body member further comprising a plurality of generally uniformlyspaced apart circumferentially disposed discrete projections about theouter surface of said body member for receiving and at least partiallypositioning therebetween a strap or similar item.

4. A strain relief device as defined in claim 3 wherein said body membercomprises a pair of hingedly coupled, integral, generally arcuateportions adapted to be secured about a selective range of saidconnectors.

5. A strain relief device as defined in claim 3 wherein said body membercomprises a pair of generally arcuate portions maintained in variablespaced apart relation and integrally coupled together by web meanscoupled to and extending therebetween.

6. A strain relief device comprising: a generally tubular body memberhaving a first end and a second end; a pair of generally arcuateclamping arms in opposing, generally diametrical, spaced-apart relation;and resilient coupling means extending outwardly from said second end ofsaid body member generally longitudinally of the axis thereof, couplingsaid clamping arms to said body member; said clamping arms and saidresilient coupling means, together with said body member, being formedof a unitary integral structure; each of said clamping arms having strapreceiving means projecting generally outwardly therefrom; one of saidstrap receiving means having an aperture therethrough disposed generallynormal to the plane thereof, and the other of said strap receiving meanscomprising a hooklike projection in generally aligned axial relationwith the longitudinal axis of said body member; said strap receivingmeans being adapted to selectively engage and at least partiallydetachably confine therein a strap or similar item disposed about saidclamping arm to detachably secure said arm to a cable or similar itemadjacent thereto; the inner surface of said body member having a seriesof interruptions thereon for intimately engaging the outer surface of aconnector or similar item.

1. A strain relief device comprising: a generally tubular body memberhaving a first end and a second end; at least one generally arcuateclamping arm; and resilient coupling means extending outwardly from saidsecond end of said body member generally longitudinally of the axisthereof, coupling said clamping arm to said body member; said clampingarm and said resilient coupling means, together with said body member,being formed of a unitary integral structure; said clamping arm havingstrap receiving means having an aperture therethrough disposed generallynormal to the plane thereof and projecting generally outwardlytherefrom, adapted to selectively engage and at least partiallydetachably confine therein a strap or similar item disposed about saidclamping arm to detachably secure said arm to a cable or similar itemadjacent thereto; the inner surface of said body member having a seriesof interruptions thereon for intimately engaging the outer surface of aconnector or similar item.
 2. A strain relief device comprising: agenerally tubular body member having a first end and a second end; atleast one generally arcuate clamping arm; and resilient coupling meansextending outwardly from said second end of said body member generallylongitudinally of the axis thereof, coupling said clamping arm to saidbody member; said clamping arm and said resilient coupling means,together with said body member, being formed of a unitary integralstructure; said clamping arm having strap receiving means comprising ahooklike projection in generally aligned axial relation with thelongitudinal axis of said body member, the open end of said hooklikeprojection being directed generally towards said body member and adaptedto selectively engage and at least partially detachably confine thereina strap or similar item disposed about said clamping arm to detachablysecure said arm to a cable or similar item adjacent thereto; the innersurface of said body member having a series of interruptions thereon forintimately engaging the outer surface of a connector or similar item. 3.A strain relief device comprising a generally tubular body member havinga first end and second end; at least one generally arcuate clamping arm;and resilient coupling means extending outwardly from said second end ofsaid body member generally longitudinally of the axis thereof, couplingsaid clamping arm to said body member; said clamping arm and saidresilient coupling means, together with said body member, being formedof a unitary integral structure; said clamping arm having strapreceiving means projecting generally outwardly therefrom, adapted toselectively engage and at least partially detachably confine therein astrap or similar item disposed about said clamping arm to detachablysecure said arm to a cable or similar item adjacent thereto; the innersurface of said body member having a series of interruptions thereon forintimately engaging the outer surface of a connector or similar item;said body member further comprising a plurality of generally uniformlyspaced apart circumferentially disposed discrete projections about theouter surface of said body member for receiving and at least partiallypositioning therebetween a strap or similar item.
 4. A strain reliefdevice as defined in claim 3 wherein said body member comprises a pairof hingedly coupled, integral, generally arcuate portions adapted to besecured about a selective range of said connectors.
 5. A strain reliefdevice as defined in claim 3 wherein said body member comprises a pairof generally arcuate portions maintained in variable spaced apartrelation and integrally coupled together by web means coupled to andextending therebetween.
 6. A strain relief device comprising: agenerally tuBular body member having a first end and a second end; apair of generally arcuate clamping arms in opposing, generallydiametrical, spaced-apart relation; and resilient coupling meansextending outwardly from said second end of said body member generallylongitudinally of the axis thereof, coupling said clamping arms to saidbody member; said clamping arms and said resilient coupling means,together with said body member, being formed of a unitary integralstructure; each of said clamping arms having strap receiving meansprojecting generally outwardly therefrom; one of said strap receivingmeans having an aperture therethrough disposed generally normal to theplane thereof, and the other of said strap receiving means comprising ahooklike projection in generally aligned axial relation with thelongitudinal axis of said body member; said strap receiving means beingadapted to selectively engage and at least partially detachably confinetherein a strap or similar item disposed about said clamping arm todetachably secure said arm to a cable or similar item adjacent thereto;the inner surface of said body member having a series of interruptionsthereon for intimately engaging the outer surface of a connector orsimilar item.